L. Alfonsi, N. Bergeot, P. J. Cilliers, G. D. Franceschi, L. Baddeley, E. Correia, D. D. Mauro, C.-F. Enell, M. Engebretson, R. Ghoddousi-Fard, I. Häggström, Y.-b. Ham, G. Heygster, G. Jee, A. Kero, M. Kosch, H.-J. Kwon, C. Lee, S. Lotz, L. Macotela, M. F. Marcucci, W. J. Miloch, Y. J. Morton, T. Naoi, M. Negusini, N. Partamies, B. H. Petkov, E. Pottiaux, P. Prikryl, P. R. Shreedevi, R. Slapak, L. Spogli, J. Stephenson, A. M. Triana-Gómez, O. A. Troshichev, R. V. Malderen, J. M. Weygand, and S. Zou. Review of Environmental Monitoring by Means of Radio Waves in the Polar Regions: From Atmosphere to Geospace. Surveys in Geophysics, volume 43, issue 6, 2022 . Y. Yamazaki, M. Kosch, Y. Ogawa, and D. Themens. High-latitude ion temperature climatology during the International Polar Year 2007–2008. J. Space Weather Space Clim., volume 6, 2016 . C. Anderson, M. J. Kosch, M. J. Nicolls, and M. Conde. Ion-neutral coupling in Earth's thermosphere, estimated from concurrent radar and optical observations over Alaska. J. Atmos. Solar-Terr. Phys., pages 313-324, 2013 . B. Gustavsson, R. Newsome, T. B. Leyser, M. J. Kosch, L. Norin, M. McCarrick, T. Pedersen, and B. J. Watkins. First observations of X-mode suppression of O-mode HF enhancements at 6300 A . Geophys. Res. Lett., volume 36, 2009 . M. J. Kosch, B. Gustavsson, C. Heinselman, T. Pedersen, M. T. Rietveld, J. Spaleta, A. Wong, W. Wang, C. Mutiso, B. Bristow, and J. Hughes. First incoherent scatter radar observations of ionospheric heating on the second electron gyro-harmonic. J. Atmos Solar-Terr. Phys., volume 71, issue 1, pages 1959-1966, 2009 . B. Gustavsson, M. Kosch, A. Wong, T. Pedersen, C. Heinselman, C. Mutiso, B. Bristow, J. Hughes, and W. Wang. First estimates of volume distribution of HF-pump enhanced emissions at 6300 and 5577 Å: a comparison between observations and theory. Ann. Geophys., volume 26, issue 1, pages 3999-4012, 2008 . M. J. Kosch, T. Pedersen, E. Mishin, S. Oyama, J. Hughes, A. Senior, B. Watkins, and B. Bristow. Coordinated optical and radar observations of ionospheric pumping for a frequency pass through the second electron gyroharmonic at HAARP. J. Geophys. Res., volume 112, 2007 . M. J. Kosch, T. Pedersen, E. Mishin, M. Starks, E. Gerken-Kendall, D. Sentman, S. Oyama, and B. Watkins. Temporal evolution of pump beam self-focusing at the High-Frequency Active Auroral Research Program. J. Geophys. Res., volume 112, 2007 . S. Oyama, B. J. Watkins, F. T. Djuth, M. J. Kosch, P. A. Bernhardt, and C. J. Heinselman. Persistent enhancement of the HF pump-induced plasma line measured with a UHF diagnostic radar at HAARP. J. Geophys. Res., volume 111, 2006 .